In last July’s post I showed artistic impressions of a number of elements – an interesting way that imaginative artists depicted zinc, cadmium, bromine, palladium and other inhabitants of the periodic table. Recently I came across a book entitled “The Disappearing Spoon” which took my appreciation of the history of discovery and the fascinating aspects and peculiar qualities of many of the elements to a wholly new level. For all readers of this blog who have an interest in chemistry, this book is essential reading.

Just to start off, the “disappearing spoon” is made of gallium, a metal that looks like aluminum and melts at 84 degrees F . A popular trick, it seems, was to make a spoon out of Gallium and give it to your guest for tea, who would watch the gallium melt in his cup of Earl Grey before his very eyes. Now for some other insights:

Who knew that Europium is used to foil counterfitting of Euro notes? Incorporated in the printing ink are randomly oriented fibers impregrated with this material. When subjected to a special laser, the note turns dark but a sketch of Europe, stars and other objects shine in different color lights. The fluorescence caused by Europium molecules is due to the element’s absorption of high energy (UV) lights and emission of visible light in the different colors.

Even now, China controls the supply of rare earth metals. in part because Chinese lanthanide ores are found close to the surface. Marco Polo introduced porcelain to Europe, but no “china” manufacturer was, for decades, able to make this extremely tough yet translucent material. Finally, a quarry near the Swedish village of Ytterby, contained a mixture of feldspar, kaoline and some rare earths that was fired up to produce porcelain at the very high furnace temperatures required. That’s how the rare earth element Yttrium received its name.

Then there is the metal Tungsten, whose characteristics when combined with steel in an extremely high melting alloy, became essential when artillery shells from both Allied and German guns caused melting of the gun barrels. Portugal, then the main source for tungsten, sold the metal ore to both belligerants at exorbitant prices, making the dictator Salazar a very wealthy man. Churchill eventually convinced him to stop selling to Hitler.

And include me among those who didn’t learn or forgot that Robert Bunsen, of Bunsen burner fame, was the scientist who discovered that each element of the periodic table emits sharp, narrow characteristic bands of colored light when heated. Hydrogen, for example, emits one red, one yellowish green, one baby blue and one indigo band. He built the first crude spectroscope using a prism inside a cigar box and adjusted his eponymous burner to achieve a very hot, blue flame, necessary to excite the elements. From that point on, it was no longer necessary to disintegrate elements to aid in their identification.